This standard applies to logarithmic quantities and units.Quantities that can be expressed as the logarithm of a dimensionless quantity, such as the ratio of two physical quantities of the same kind, can be regarded and treated in different ways. In many cases, differences in principle do not affect the practical treatment.Logarithmic quantities are here treated in a way that makes it possible, for example, to express the attenuation of a certain linear two-terminal network by the equally valid expressions A = 4,6 nepers = 4,0 bels = 40 decibels, where 4,6, 4,0 and 40 are regarded as numerical values and "neper", "bel" and "decibel" as units with specified relationships.The fact that this standard is based on certain principles and assumptions implies no opinion whether any other principle or assumption is "right" or "wrong". This standard relates to the handling of logarithmic quantities, without regard to their interpretation or specific application.The fact that only some logarithmic quantities are particularly dealt with here does not imply that other logarithmic quantities do not exist. It is possible that other logarithmic quantities will be particularly dealt with in a later edition or separately.